The purpose of this study is to illustrate how to transform number-correct raw scores into scale scores using BCTEST scores as an example. In this study, two methods of transforming raw scores into scale scores including using extended beta-binomial model or IRT to obtain the raw score distribution will be described and the results given by these methods will be also compared and discussed. The findings of this study indicate both extended beta-binomial model and item response model fitted the distributions of raw score well and gave similar results. The simulated data used in this study were unimodal, but in the real test it was found that the raw score distribution for English test was bimodal. More studies are needed before the findings given by this study are generalized to other situations.